Samples of end-matched preservative-treated dimensional lumber have been exposed in ground contact for 10 years at Forintek's two test plots in Ontario. At Kincardine, the site supports a colony of the Eastern subterranean termite, Reticulitermes flavipes (Kollar); at Petawawa, there is no termite activity. While decay is somewhat more pronounced at Kincardine, the major difference between the sites is due to the presence or absence of termite activity. Termites are a much more serious threat than decay for treated wood with shallow preservative penetration.